• 한국금형공학회:학술대회논문집
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• 2008.06a
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• pp.27-30
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• 2008

It was investigated that two rods of aluminium can be welded by hot extru-welding method with extru-welding dies, and that the extru-welding on the welding surface were analyzed by computer simulation according to the steped shapes of welding dies. It was known by computer simulation that welding pressure on the welding section of rods welded using extru-welding dies and that the welding pressure on the welding section of rods using extru-welding dies is lowerer than the welding pressure of rods using stepped welding dies. And it was known by experiments that two rods of aluminium can be welded on the end sections by hot extru-welding method using fan-shaped stepped welding dies without relative rotational movement of contacted aluminium rods needed for the purpose of friction heating and pressure.

• Transactions of Materials Processing
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• v.23 no.5
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• pp.282-288
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• 2014

It is difficult to control welding variables during spot welding of non-ferrous metals like aluminum because of the low electrical resistance of the material. It has been suggested that a solid state welding process such as friction stir spot welding or extru-spot welding can be used to spot weld aluminum plates. In the extru-spot welding, there is a need to increase the weld strength by improving the shape of the welding die. The current study shows that the weld strength for an extru-spot welding can be increased by using a pin placed on the inside of the upper electrode in the welding die. In the current study, the deformed shape of the insert rivet and the stress distribution in the welding zone were analyzed by simulation. Extru-rivet spot welding experiments were performed by changing the height of pin on the inside of the upper electrode. From the experimental result, it is shown that the weld strength for an extru-rivet spot welding can be increased by adjusting the height of the pin. The optimal shape of the deformed rivet after the extru-rivet spot welding can be observed from the simulation results. The deformed shape of the insert rivet can also be controlled by the height of pin.

• Transactions of Materials Processing
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• v.11 no.6
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• pp.495-502
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• 2002

The welding pressure in extru bending process is affected by the shape of welding chamber of porthole die. It is very important to increase the welding pressure when the tube should be extruded particulary from four billets of the materials. The high circumferential stress of the tube can make the welding pressure increase during the extru-bending. In order to increase the circumferential stress, it is necessary to make the billets pass through the narrow gap between the conical die and the conical plug. This paper describes the welding pressure by the experiments and the analysis with the two types of the chamber. One of them is the chamber between the flat die and straight mandrel, and the other one is the chamber between the conical die and conical plug. The results of the experiments and the analysis shows that the conical chamber makes the welding pressure increase by the effect of the reducing diameter of tube and the welding pressure by the conical dic and plug is stronger than the welding pressure by the flat die and straight mandrel.

• Design & Manufacturing
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• v.2 no.5
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• pp.34-38
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• 2008

It was investigated that two rods of aluminium can be welded by hot extru-pressure welding method with stepped welding dies, and that the welding pressure on the welding surface were analyzed by computer simulation according to the stepped shapes of welding dies. It was known by computer simulation that welding pressure on the welding section of rods welded using stepped welding dies. And it was known by experime- nts that two rods of aluminium can be welded on the end sections by hot pressure welding method using stepped welding dies without relative rotational movement of contacted aluminium rods needed for the purpose of friction heating and pressure.

• Transactions of Materials Processing
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• v.17 no.4
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• pp.284-291
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• 2008

It was investigated that two rods of aluminum can be welded by hot extru-pressure welding method with stepped welding dies, and that the welding pressure and metal flow on the welding surface were analyzed by computer simulation according to the stepped shapes of welding dies. It was known by computer simulation that welding pressure on the welding section of rods welded using stepped welding dies could be higher than the welding pressure of aluminum rods without using stepped welding die. And it was known by experiments that two rods of aluminum can be welded on the end sections by hot extru-pressure welding method using stepped welding dies without relative rotational movement of contacted aluminum rods in the case of friction welding of rods.

• Transactions of Materials Processing
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• v.19 no.8
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• pp.460-467
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• 2010

It was studied that two plates of aluminum can be welded by extru-riveting experiments with extru-rivet welding dies, and that the welding strength and metal flow on the welding section were analyzed by computer simulation according to the welding variable such as the diameter of extrusion insert dies. It was known by computer simulation that welding strength on the welding section of plates could be influenced by the diameter of extrusion insert dies. And it was known by experiments that two plates of aluminum can be welded on a spot point on aluminum plate by extru-rivet welding process, and that welding strength is higher and higher if the diameter of extrusion insert die is smaller and smaller, and that welding strength is the highest when diameter of extrusion insert dies is ${\emptyset}4.2$mm in the case that the diameter of rivet is 5 mm, when aluminum 5052 two plates with 1.5 mm thickness and one plate with 3mm thickness for rivet plate are used as welding material.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.359-362
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• 2003

The bending phenomenon has been known to be occurred by the different of velocity at the die exit. The difference of velocity at the die exit section can be obtained by the different velocity of billets through the multi-hole container and by the cohesion of billet inside the porthole die chamber. The bending phenomenon can be controlled by the different hole diameter. The experiments using aluminium material for the curved tube product had been done. The results of the experiment show that the curved tube product can be formed by the extru-bending process without the defects such as the distortion of section and the thickness change of the wall of tube and the folding and wrinkling. It is known that the welding and extruding of each billet has done simultaneously although the curved tube is extruded with four billets.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.285-288
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• 2003

The bending phenomenon during extruding one product using four billets can be obtain by the difference of hole diameters in the multi-hole container. The difference of hole diameter caused the difference of billet amount inserted in the die cavity. As results, it can bend during extruding products by the different amount of two billets and by the cohesion of billets in the porthole dies cavity. And the bending curvature can be controlled by the size of holes and billets. The experiments using aluminium material had been done for the rectangular and square curved tube product. The results of the experiment show that the curved aluminum tube product can be bended by the extru-bending process without the defects such as the distortion of section and the thickness change of the wall of tube and the folding and wrinkling. The curvature of product is affected by shape of cross section and the difference of billet diameters. It is known that the welding and extruding and bending can be done simultaneously in the die cavity when a rectangular hollow curved tube would be extruded by porthole dies using four different size billets made of aluminum material.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.120-123
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• 2004

The bending phenomenon has been known to be occurred by the difference of velocity at the die exit. The difference of velocity at the die exit section can be obtained by the different velocity of billets inside die chamber after passing the multi-hole container. The curvature can be controlled by the two variables, the one of them is the different velocity of billets through the multi-hole container, the other is the difference of hole diameter. The bending phenomenon during extruding using four billets can be obtained by the difference of hole diameters in the multi-hole container or by the difference of relative velocity of billet inserted in the container. As results of DEFORM-3D analysis, it can be shown that bending can be obtained during extruding by the difference of relative velocity of two billets or by the difference of hole diameter, and the amount of curvature is increased by the difference of velocity and diameter. According to the shape of products, the curvature of rectangular section is bigger than the curvature of regular square section. And, it is estimated that, because the stress on the welding line is much higher than yield stress of material, the bonding of four billets can be obtained.